INTRODUCTION. Outpatient (OPT) thyroid surgery is increasing, with patient selection being pivotal for safety. While numerous studies exist, most are retrospective and encompass both benign and malignant cases. METHODS. We conducted a randomised clinical trial on patients undergoing hemithyroidectomy for benign thyroid disease. Participants were assigned to OPT or inpatient groups. We collected data on complications, failure to discharge on surgery day, post-operative pain, nausea, sleep quality and patient satisfaction. RESULTS. Among 97 patients, 27.5% (14/51) in the OPT group could not be discharged on the day of surgery due to minor complications, primarily nausea (36%) and neck swelling (29%). No reoperations were needed. Though OPT patients exhibited a higher rate of minor complications (29%), they reported less post-operative nausea, better sleep and a faster return to normal activity. CONCLUSIONS. Discharge on the day of surgery is not always possible with OPT thyroid surgery. However, our findings suggest that OPT hemithyroidectomy for benign cases can be both safe and feasible for a selected group of patients. © 2024, Almindelige Danske Laegeforening. All rights reserved.